Add backend support for multiple tables

src/asm2wasm.h

@@ -660,11 +660,11 @@ void Asm2WasmBuilder::processAsm(Ref ast) {
           // TODO: when not using aliasing function pointers, we could merge them by noticing that
           //       index 0 in each table is the null func, and each other index should only have one
           //       non-null func. However, that breaks down when function pointer casts are emulated.
-          functionTableStarts[name] = wasm.table.names.size(); // this table starts here
+          functionTableStarts[name] = wasm.getDefaultTable()->values.size(); // this table starts here
           Ref contents = value[1];
           for (unsigned k = 0; k < contents->size(); k++) {
             IString curr = contents[k][1]->getIString();
-            wasm.table.names.push_back(curr);
+            wasm.getDefaultTable()->values.push_back(curr);
           }
         } else {
           abort_on("invalid var element", pair);

src/binaryen-c.cpp

@@ -586,7 +586,7 @@ BinaryenExpressionRef BinaryenSelect(BinaryenModuleRef module, BinaryenExpressio
 }
 BinaryenExpressionRef BinaryenReturn(BinaryenModuleRef module, BinaryenExpressionRef value) {
   auto* ret = Builder(*((Module*)module)).makeReturn((Expression*)value);
- 
+
   if (tracing) {
     auto id = noteExpression(ret);
     std::cout << "  expressions[" << id << "] = BinaryenReturn(the_module, expressions[" << expressions[value] << "]);\n";
@@ -730,7 +730,7 @@ void BinaryenSetFunctionTable(BinaryenModuleRef module, BinaryenFunctionRef* fun
 
   auto* wasm = (Module*)module;
   for (BinaryenIndex i = 0; i < numFuncs; i++) {
-    wasm->table.names.push_back(((Function*)funcs[i])->name);
+    wasm->getDefaultTable()->values.push_back(((Function*)funcs[i])->name);
   }
 }
 

src/passes/DuplicateFunctionElimination.cpp

@@ -123,10 +123,12 @@ struct DuplicateFunctionElimination : public Pass {
         replacerRunner.add<FunctionReplacer>(&replacements);
         replacerRunner.run();
         // replace in table
-        for (auto& name : module->table.names) {
-          auto iter = replacements.find(name);
-          if (iter != replacements.end()) {
-            name = iter->second;
+        for (auto& curr : module->tables) {
+          for (auto& name : curr->values) {
+            auto iter = replacements.find(name);
+            if (iter != replacements.end()) {
+              name = iter->second;
+            }
           }
         }
         // replace in start

src/passes/Print.cpp

@@ -576,7 +576,7 @@ struct PrintSExpression : public Visitor<PrintSExpression> {
   }
   void visitTable(Table *curr) {
     printOpening(o, "table");
-    for (auto name : curr->names) {
+    for (auto name : curr->values) {
       o << ' ';
       printName(name);
     }
@@ -647,9 +647,9 @@ struct PrintSExpression : public Visitor<PrintSExpression> {
       visitGlobal(child.get());
       o << maybeNewLine;
     }
-    if (curr->table.names.size() > 0) {
+    for (auto& child : curr->tables) {
       doIndent(o, indent);
-      visitTable(&curr->table);
+      visitTable(child.get());
       o << maybeNewLine;
     }
     for (auto& child : curr->functions) {

src/passes/RemoveUnusedFunctions.cpp

@@ -39,8 +39,10 @@ struct RemoveUnusedFunctions : public Pass {
       root.push_back(module->getFunction(curr->value));
     }
     // For now, all functions that can be called indirectly are marked as roots.
-    for (auto& curr : module->table.names) {
-      root.push_back(module->getFunction(curr));
+    for (auto& child : module->tables) {
+      for (auto& curr : child->values) {
+        root.push_back(module->getFunction(curr));
+      }
     }
     // Compute function reachability starting from the root set.
     DirectCallGraphAnalyzer analyzer(module, root);

src/passes/ReorderFunctions.cpp

@@ -38,8 +38,10 @@ struct ReorderFunctions : public WalkerPass<PostWalker<ReorderFunctions, Visitor
     for (auto& curr : module->exports) {
       counts[curr->value]++;
     }
-    for (auto& curr : module->table.names) {
-      counts[curr]++;
+    for (auto& child : module->tables) {
+      for (auto& curr : child->values) {
+        counts[curr]++;
+      }
     }
     std::sort(module->functions.begin(), module->functions.end(), [this](
       const std::unique_ptr<Function>& a,

src/wasm-binary.h

@@ -480,7 +480,7 @@ class WasmBinaryWriter : public Visitor<WasmBinaryWriter, void> {
     writeSignatures();
     writeImports();
     writeFunctionSignatures();
-    writeFunctionTable();
+    writeFunctionTables();
     writeMemory();
     writeGlobals();
     writeExports();
@@ -556,7 +556,7 @@ class WasmBinaryWriter : public Visitor<WasmBinaryWriter, void> {
     finishSection(start);
   }
 
-  int32_t getFunctionTypeIndex(Name type) {
+  Index getFunctionTypeIndex(Name type) {
     // TODO: optimize
     for (size_t i = 0; i < wasm->functionTypes.size(); i++) {
       if (wasm->functionTypes[i]->name == type) return i;
@@ -685,7 +685,7 @@ class WasmBinaryWriter : public Visitor<WasmBinaryWriter, void> {
 
   void writeExports() {
     if (wasm->exports.size() == 0) return;
-    if (debug) std::cerr << "== writeexports" << std::endl;
+    if (debug) std::cerr << "== writeExports" << std::endl;
     auto start = startSection(BinaryConsts::Section::ExportTable);
     o << U32LEB(wasm->exports.size());
     for (auto& curr : wasm->exports) {
@@ -724,8 +724,8 @@ class WasmBinaryWriter : public Visitor<WasmBinaryWriter, void> {
     assert(mappedImports.count(name));
     return mappedImports[name];
   }
-  
-  std::map<Name, uint32_t> mappedFunctions; // name of the Function => index 
+
+  std::map<Name, uint32_t> mappedFunctions; // name of the Function => entry index
   uint32_t getFunctionIndex(Name name) {
     if (!mappedFunctions.size()) {
       // Create name => index mapping.
@@ -738,13 +738,18 @@ class WasmBinaryWriter : public Visitor<WasmBinaryWriter, void> {
     return mappedFunctions[name];
   }
 
-  void writeFunctionTable() {
-    if (wasm->table.names.size() == 0) return;
-    if (debug) std::cerr << "== writeFunctionTable" << std::endl;
+  void writeFunctionTables() {
+    if (wasm->tables.size() == 0) return;
+    if (debug) std::cerr << "== writeFunctionTables" << std::endl;
     auto start = startSection(BinaryConsts::Section::FunctionTable);
-    o << U32LEB(wasm->table.names.size());
-    for (auto name : wasm->table.names) {
-      o << U32LEB(getFunctionIndex(name));
+    assert(wasm->tables.size() == 1);
+    // o << U32LEB(wasm->tables.size());
+    for (auto& curr : wasm->tables) {
+      if (debug) std::cerr << "write one" << std::endl;
+      o << U32LEB(curr->values.size());
+      for (auto name : curr->values) {
+        o << U32LEB(getFunctionIndex(name));
+      }
     }
     finishSection(start);
   }
@@ -1256,7 +1261,7 @@ class WasmBinaryBuilder {
       else if (match(BinaryConsts::Section::ExportTable)) readExports();
       else if (match(BinaryConsts::Section::Globals)) readGlobals();
       else if (match(BinaryConsts::Section::DataSegments)) readDataSegments();
-      else if (match(BinaryConsts::Section::FunctionTable)) readFunctionTable();
+      else if (match(BinaryConsts::Section::FunctionTable)) readFunctionTables();
       else if (match(BinaryConsts::Section::Names)) readNames();
       else {
         std::cerr << "unfamiliar section: ";
@@ -1638,9 +1643,10 @@ class WasmBinaryBuilder {
       }
     }
 
-    for (size_t index : functionTable) {
-      assert(index < wasm.functions.size());
-      wasm.table.names.push_back(wasm.functions[index]->name);
+    for (auto& pair : functionTable) {
+      assert(pair.first < wasm.tables.size());
+      assert(pair.second < wasm.functions.size());
+      wasm.tables[pair.first]->values.push_back(wasm.functions[pair.second]->name);
     }
   }
 
@@ -1660,14 +1666,20 @@ class WasmBinaryBuilder {
     }
   }
 
-  std::vector<size_t> functionTable;
+  std::vector<std::pair<size_t, size_t>> functionTable;
 
-  void readFunctionTable() {
-    if (debug) std::cerr << "== readFunctionTable" << std::endl;
-    auto num = getU32LEB();
-    for (size_t i = 0; i < num; i++) {
-      auto index = getU32LEB();
-      functionTable.push_back(index);
+  void readFunctionTables() {
+    if (debug) std::cerr << "== readFunctionTables" << std::endl;
+    size_t numTables = 1; // getU32LEB()
+    for (size_t i = 0; i < numTables; i++) {
+      if (debug) std::cerr << "read one" << std::endl;
+      auto curr = new Table;
+      auto size = getU32LEB();
+      for (size_t j = 0; j < size; j++) {
+        auto index = getU32LEB();
+        functionTable.push_back(std::make_pair<>(i, index));
+      }
+      wasm.addTable(curr);
     }
   }
 

src/wasm-interpreter.h

@@ -666,9 +666,10 @@ class ModuleInstance {
         LiteralList arguments;
         Flow flow = generateArguments(curr->operands, arguments);
         if (flow.breaking()) return flow;
+        Table *table = instance.wasm.getDefaultTable();
         size_t index = target.value.geti32();
-        if (index >= instance.wasm.table.names.size()) trap("callIndirect: overflow");
-        Name name = instance.wasm.table.names[index];
+        if (index >= table->values.size()) trap("callIndirect: overflow");
+        Name name = table->values[index];
         Function *func = instance.wasm.getFunction(name);
         if (func->type.is() && func->type != curr->fullType) trap("callIndirect: bad type");
         if (func->params.size() != arguments.size()) trap("callIndirect: bad # of arguments");

src/wasm-linker.cpp

@@ -117,22 +117,20 @@ void Linker::layout() {
 
   // Pre-assign the function indexes
   for (auto& pair : out.indirectIndexes) {
-    if (functionIndexes.count(pair.first) != 0 ||
-        functionNames.count(pair.second) != 0) {
-      Fatal() << "Function " << pair.first << " already has an index " <<
-          functionIndexes[pair.first] << " while setting index " << pair.second;
+    Index tableIndex = Table::kDefault;
+    Table *table = out.getIndirectTable(tableIndex);
+    if (functionIndexes.count(pair.second) != 0) {
+      Fatal() << "Function " << pair.second << " already has an index " <<
+          functionIndexes[pair.second].first << " while setting index " << pair.first;
     }
     if (debug) {
-      std::cerr << "pre-assigned function index: " << pair.first << ": "
-                << pair.second << '\n';
+      std::cerr << "pre-assigned function index: " << pair.second << ": "
+                << pair.first << '\n';
     }
-    functionIndexes[pair.first] = pair.second;
-    functionNames[pair.second] = pair.first;
-  }
-
-  // Emit the pre-assigned function names in sorted order
-  for (const auto& P : functionNames) {
-    out.wasm.table.names.push_back(P.second);
+    assert(table->values.size() == pair.first);
+    table->values.push_back(pair.second);
+    auto indexes = std::make_pair(tableIndex, pair.first);
+    functionIndexes[pair.second] = indexes;
   }
 
   for (auto& relocation : out.relocations) {
@@ -170,6 +168,15 @@ void Linker::layout() {
       }
     }
   }
+
+  // Create the actual tables in the underlying module. This is delayed because
+  // table references may be out of order, and the underlying object is a vector.
+  Index counter = 0;
+  for (auto& pair : out.tables) {
+    if (pair.first != counter++) Fatal() << "Tables are nonconsecutive!" << '\n';
+    out.wasm.addTable(pair.second);
+  }
+
   if (!!startFunction) {
     if (out.symbolInfo.implementedFunctions.count(startFunction) == 0) {
       Fatal() << "Unknown start function: `" << startFunction << "`\n";
@@ -206,9 +213,11 @@ void Linker::layout() {
   }
 
   // ensure an explicit function type for indirect call targets
-  for (auto& name : out.wasm.table.names) {
-    auto* func = out.wasm.getFunction(name);
-    func->type = ensureFunctionType(getSig(func), &out.wasm)->name;
+  for (auto& table : out.wasm.tables) {
+    for (auto& name : table->values) {
+      auto* func = out.wasm.getFunction(name);
+      func->type = ensureFunctionType(getSig(func), &out.wasm)->name;
+    }
   }
 }
 
@@ -371,14 +380,17 @@ void Linker::emscriptenGlue(std::ostream& o) {
 
 Index Linker::getFunctionIndex(Name name) {
   if (!functionIndexes.count(name)) {
-    functionIndexes[name] = out.wasm.table.names.size();
-    out.wasm.table.names.push_back(name);
+    Index tableIndex = Table::kDefault;
+    Table *table = out.getIndirectTable(tableIndex);
+    functionIndexes[name] = std::make_pair(tableIndex, table->values.size());
+    table->values.push_back(name);
     if (debug) {
       std::cerr << "function index: " << name << ": "
-                << functionIndexes[name] << '\n';
+                << functionIndexes[name].first << " "
+                << functionIndexes[name].second << '\n';
     }
   }
-  return functionIndexes[name];
+  return functionIndexes[name].second;
 }
 
 bool hasI64ResultOrParam(FunctionType* ft) {
@@ -390,7 +402,7 @@ bool hasI64ResultOrParam(FunctionType* ft) {
 }
 
 void Linker::makeDummyFunction() {
-  assert(out.wasm.table.names.empty());
+  assert(out.wasm.tables.empty());
   bool create = false;
   // Check if there are address-taken functions
   for (auto& relocation : out.relocations) {
@@ -410,27 +422,29 @@ void Linker::makeDummyFunction() {
 void Linker::makeDynCallThunks() {
   std::unordered_set<std::string> sigs;
   wasm::Builder wasmBuilder(out.wasm);
-  for (const auto& indirectFunc : out.wasm.table.names) {
-    // Skip generating thunks for the dummy function
-    if (indirectFunc == dummyFunction) continue;
-    std::string sig(getSig(out.wasm.getFunction(indirectFunc)));
-    auto* funcType = ensureFunctionType(sig, &out.wasm);
-    if (hasI64ResultOrParam(funcType)) continue; // Can't export i64s on the web.
-    if (!sigs.insert(sig).second) continue; // Sig is already in the set
-    std::vector<NameType> params;
-    params.emplace_back("fptr", i32); // function pointer param
-    int p = 0;
-    for (const auto& ty : funcType->params) params.emplace_back(std::to_string(p++), ty);
-    Function* f = wasmBuilder.makeFunction(std::string("dynCall_") + sig, std::move(params), funcType->result, {});
-    Expression* fptr = wasmBuilder.makeGetLocal(0, i32);
-    std::vector<Expression*> args;
-    for (unsigned i = 0; i < funcType->params.size(); ++i) {
-      args.push_back(wasmBuilder.makeGetLocal(i + 1, funcType->params[i]));
+  for (const auto& table : out.wasm.tables) {
+    for (const auto& indirectFunc : table->values) {
+      // Skip generating thunks for the dummy function
+      if (indirectFunc == dummyFunction) continue;
+      std::string sig(getSig(out.wasm.getFunction(indirectFunc)));
+      auto* funcType = ensureFunctionType(sig, &out.wasm);
+      if (hasI64ResultOrParam(funcType)) continue; // Can't export i64s on the web.
+      if (!sigs.insert(sig).second) continue; // Sig is already in the set
+      std::vector<NameType> params;
+      params.emplace_back("fptr", i32); // function pointer param
+      int p = 0;
+      for (const auto& ty : funcType->params) params.emplace_back(std::to_string(p++), ty);
+      Function* f = wasmBuilder.makeFunction(std::string("dynCall_") + sig, std::move(params), funcType->result, {});
+      Expression* fptr = wasmBuilder.makeGetLocal(0, i32);
+      std::vector<Expression*> args;
+      for (unsigned i = 0; i < funcType->params.size(); ++i) {
+        args.push_back(wasmBuilder.makeGetLocal(i + 1, funcType->params[i]));
+      }
+      Expression* call = wasmBuilder.makeCallIndirect(funcType, fptr, args);
+      f->body = call;
+      out.wasm.addFunction(f);
+      exportFunction(f->name, true);
     }
-    Expression* call = wasmBuilder.makeCallIndirect(funcType, fptr, args);
-    f->body = call;
-    out.wasm.addFunction(f);
-    exportFunction(f->name, true);
   }
 }